Solanone is known as a useful tobacco flavorant and flavor enhancer. It is a mixture consisting primarily of the compound: ##STR1## and, in addition, a small amount of the compound having the structure: ##STR2##
Norsolanadione is another compound known to be useful as a tobacco flavorant and in augmenting or enhancing the aroma and taste of smoking tobacco. Norsolanadione has the structure: ##STR3## Both norsolanadione and solanone have been previously synthesized using cumbersome, economically unfeasible reactions, e.g. reactions including the Wittig or Emmons reaction.
The compound having the structure: ##STR4## has been isolated from Burley tobacco flavor as set forth in Chem. Abstracts 1974, 35704g and in the article by Demole et al, Helv. Chim. Acta, 1974, 57(1) pages 192-4. This material known as "solanone hydrate" is also shown to be synthesized in Chem. Abstracts 85:108821n via a complex, multi-step synthesis.
The present invention provides an efficient, low cost synthesis for preparation of solanone, norsolanadione and solanone hydrate having the structure: ##STR5##